Indexing Columns as Sections
To index tags as sections, you can optionally create field sections with BASIC_SECTION_GROUP.
Note: No section group is created when you use the MULTI_COLUMN_DATASTORE. To create sections for these tags, you must create a section group.
When you use expressions or functions, the tag is composed of the first 30 characters of the expression unless a column alias is used.
For example, if your expression is as follows:
exec ctx_ddl.set_attibute('mymds', 'columns', '4 + 17');
then it produces the following virtual text:
<4 + 17>
21
</4 + 17>
If your expression is as follows:
exec ctx_ddl.set_attibute('mymds', 'columns', '4 + 17 col1');
then it produces the following virtual text:
<col1>
21
<col1>
The tags are in uppercase unless the column name or column alias is in lowercase and surrounded by double quotation marks. For example:
exec ctx_ddl.set_attibute('mymds', 'COLUMNS', 'foo');
This produces the following virtual text:
<FOO>
content of foo
</FOO>
For lowercase tags, use the following:
exec ctx_ddl.set_attibute('mymds', 'COLUMNS', 'foo "foo"');
This expression produces:
<foo>
content of foo
</foo>